Yellowtail

Examples for Processing (BETA) version 127+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

Textured Sphere by Mike 'Flux' Chang (cleaned up by Aaron Koblin). Based on code by Toxi.

A 3D textured sphere with simple rotation control. Note: Controls will be inverted when sphere is upside down. Use an "arc ball" to deal with this appropriately.


import processing.opengl.*;

PImage bg;
PImage texmap;

int sDetail = 35;  //Sphere detail setting
float rotationX = 0;
float rotationY = 0;
float velocityX = 0;
float velocityY = 0;
float globeRadius = 300;
float pushBack = 0;

float[] cx,cz,sphereX,sphereY,sphereZ;
float sinLUT[];
float cosLUT[];
float SINCOS_PRECISION = 0.5f;
int SINCOS_LENGTH = int(360.0 / SINCOS_PRECISION);


void setup()
{
  size(640, 480, OPENGL);  
  texmap = loadImage("world32k.jpg");    
  initializeSphere(sDetail);
}

void draw()
{    
  background(0);            
  renderGlobe(); 
}


void renderGlobe() 
{
  pushMatrix();
  translate(width/2.0, height/2.0, pushBack);
  pushMatrix();
  noFill();
  stroke(255,200);
  strokeWeight(2);
  smooth();
  popMatrix();
  lights();    
  pushMatrix();
  rotateX( radians(-rotationX) );  
  rotateY( radians(270 - rotationY) );
  fill(200);
  noStroke();
  textureMode(IMAGE);  
  texturedSphere(globeRadius, texmap);
  popMatrix();  
  popMatrix();
  rotationX += velocityX;
  rotationY += velocityY;
  velocityX *= 0.95;
  velocityY *= 0.95;
  
  // Implements mouse control (interaction will be inverse when sphere is  upside down)
  if(mousePressed){
    velocityX += (mouseY-pmouseY) * 0.01;
    velocityY -= (mouseX-pmouseX) * 0.01;
  }
}

void initializeSphere(int res)
{
  sinLUT = new float[SINCOS_LENGTH];
  cosLUT = new float[SINCOS_LENGTH];

  for (int i = 0; i < SINCOS_LENGTH; i++) {
    sinLUT[i] = (float) Math.sin(i * DEG_TO_RAD * SINCOS_PRECISION);
    cosLUT[i] = (float) Math.cos(i * DEG_TO_RAD * SINCOS_PRECISION);
  }

  float delta = (float)SINCOS_LENGTH/res;
  float[] cx = new float[res];
  float[] cz = new float[res];
  
  // Calc unit circle in XZ plane
  for (int i = 0; i < res; i++) {
    cx[i] = -cosLUT[(int) (i*delta) % SINCOS_LENGTH];
    cz[i] = sinLUT[(int) (i*delta) % SINCOS_LENGTH];
  }
  
  // Computing vertexlist vertexlist starts at south pole
  int vertCount = res * (res-1) + 2;
  int currVert = 0;
  
  // Re-init arrays to store vertices
  sphereX = new float[vertCount];
  sphereY = new float[vertCount];
  sphereZ = new float[vertCount];
  float angle_step = (SINCOS_LENGTH*0.5f)/res;
  float angle = angle_step;
  
  // Step along Y axis
  for (int i = 1; i < res; i++) {
    float curradius = sinLUT[(int) angle % SINCOS_LENGTH];
    float currY = -cosLUT[(int) angle % SINCOS_LENGTH];
    for (int j = 0; j < res; j++) {
      sphereX[currVert] = cx[j] * curradius;
      sphereY[currVert] = currY;
      sphereZ[currVert++] = cz[j] * curradius;
    }
    angle += angle_step;
  }
  sDetail = res;
}

// Generic routine to draw textured sphere
void texturedSphere(float r, PImage t) 
{
  int v1,v11,v2;
  r = (r + 240 ) * 0.33;
  beginShape(TRIANGLE_STRIP);
  texture(t);
  float iu=(float)(t.width-1)/(sDetail);
  float iv=(float)(t.height-1)/(sDetail);
  float u=0,v=iv;
  for (int i = 0; i < sDetail; i++) {
    vertex(0, -r, 0,u,0);
    vertex(sphereX[i]*r, sphereY[i]*r, sphereZ[i]*r, u, v);
    u+=iu;
  }
  vertex(0, -r, 0,u,0);
  vertex(sphereX[0]*r, sphereY[0]*r, sphereZ[0]*r, u, v);
  endShape();   
  
  // Middle rings
  int voff = 0;
  for(int i = 2; i < sDetail; i++) {
    v1=v11=voff;
    voff += sDetail;
    v2=voff;
    u=0;
    beginShape(TRIANGLE_STRIP);
    texture(t);
    for (int j = 0; j < sDetail; j++) {
      vertex(sphereX[v1]*r, sphereY[v1]*r, sphereZ[v1++]*r, u, v);
      vertex(sphereX[v2]*r, sphereY[v2]*r, sphereZ[v2++]*r, u, v+iv);
      u+=iu;
    }
  
    // Close each ring
    v1=v11;
    v2=voff;
    vertex(sphereX[v1]*r, sphereY[v1]*r, sphereZ[v1]*r, u, v);
    vertex(sphereX[v2]*r, sphereY[v2]*r, sphereZ[v2]*r, u, v+iv);
    endShape();
    v+=iv;
  }
  u=0;
  
  // Add the northern cap
  beginShape(TRIANGLE_STRIP);
  texture(t);
  for (int i = 0; i < sDetail; i++) {
    v2 = voff + i;
    vertex(sphereX[v2]*r, sphereY[v2]*r, sphereZ[v2]*r, u, v);
    vertex(0, r, 0,u,v+iv);    
    u+=iu;
  }
  vertex(0, r, 0,u, v+iv);
  vertex(sphereX[voff]*r, sphereY[voff]*r, sphereZ[voff]*r, u, v);
  endShape();
  
}